we took our daughter out when she was 2 weeks old. probably because she was the second and the new-parent worries were behind us.
with our first, it seemed like a month before i saw the light of day. mainly because i was new to it all, didn't have anywhere that i had to go, and couldn't get used to preparing someone other than myself to leave the house, even for a 20-minute errand.
the first time i left the house alone with our son, it took me 45 minutes to pack a bag for him and get him loaded in the car just to drop off some mail at the post office around the corner from our house!